Shielded rotary toothbrush



March 16, 1943. D, s, BECKNER 2,314,117

SHIELDED ROTARY TOOTHBRUSH Filed Jan. 27, 1941 I/wnvrop, Omoar J,Bax/v52,

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Patented Mar. 16, 1943 UNITED STATES PATENT OFFICE 2,314,117 SHIELDEDROTARY TOOTHBRUSH Dwight S. Beckner, Rushville, Ind. Application January27, 1941, Serial No. 376,108

2 Claims.

This invention relates to means for brushin and cleaning teeth in onesmouth by means of a power driven brush. A primary object of theinvention is to provide a rotary driven brush which may be employed inthe mouth to brush the upper teeth downwardly from the gums and thelower teeth upwardly from their gums and at the same time guard theinner cheek wall from contact by the brush.

A still further important object of the invention is to provide not onlythe above indicated guard means but also to incorporate with the guardand brush, means to hold and present a quantity of dentifrice to bepicked up by the brush when it is being operated.

A still further important object of the invention is to provide in suchmeans as above indicated, a brush and guard structure that may besupported by a head in such manner that other like brushes and guardsmay be employed to the end that a common head may be employed by allmembers of a family with an individual guard and brush set for eachmember of the family.

These and many other objects and advantages of the invention will becomeapparent to those versed in the art from the following de scription ofone particular form of the invention as illustrated in the accompanyingdrawing, in which Fig. 1 is a view in side elevation of a structureembodying the invention in partial section;

Fig. 2, a top plan view thereof with one of the walls of the head brokenaway;

Fig. 3, a detail in longitudinal central section through the guard head;

Fig. 4, an end elevation of assembly;

Fig. 5, a transverse section in Fig. 1;

Fig. 6, a transverse in Fig. 1; and

Fig. 7, a side elevation of a dentifrice capsule to be carried by theguard.

Like characters of reference indicate like parts in the several views inthe drawing.

I form a head, generally designated by the numeral III, of such size andproportion that it may be conveniently grasped across the palm of thepersons hand and contain a suitable driving motor of any nature, such asa spring motor or an electric motor, an electric motor H being hereinindicated as the source of power. In

the guard and brush on the line 5-5 section on the line 6-8 thisrespect, the important feature is that there be presented a driven shaftI: through one end of the housing to releasably receive by its outer endin any suitable manner the end of the brush shaft l3. The shaft l2 maycarry any suitable type of engaging means for this purpose in the natureof a chuck, a simple frictional type of chuck being herein indicatedwherein the shaft l2 has a central axial conical bore entered from itsouter end to form a tapered socket to receive therein the conical end llof the brush shaft l3. The degree of taper of the socket and the end Itis made to be such that the end It will be frictionally retained withinthe socket in the shaft l 2 sufficient to form a driving connectiontherebetween and yet permit the brush shaft I3 to be pulled outwardlyfor disengagement. Whatever type of motor ll may be employed, the shaftl2 driven thereby operates at a relatively low speed, not to exceed fivehundred revolutions per minute, first, to prevent any harsh action onthe tissues within ones mouth and, secondly, to prevent centrifugalaction throwing off dentifrice from the brush to any great degree.

The brush shaft I3 is made out of any suitable material such as willhave the required structural strength for mounting and carrying a. brushI5 'spirally formed around its outer end portion.

Furthermore this shaft I: should be resilient in nature, at least tosome degree. It is desirable to have this brush formed in such mannerthat the outer end, as indicated in Fig. 4, will have bristles presentedthereacross so as to completely conceal the end of the shaft l3. Theoverall diameter of the brush is made to be that which will convenientlyfit and give satisfactory operation over the teeth. I find thatanoverall diameter of the bristles of flv-eighths of an inch to be quitesatisfactory for this purpose, particularly for adults.

To one side of the brush I5 is positioned a guard or shield It by meansof a resilient stem l'l extending substantially parallel to the shaft l3and having an end releasably entered into and frictionally retained by asocket within the head I ll. Preferably the end l8 of this stem I1 isgiven some cross-sectional shape other than round, herein shown asrectangular, to prevent rotation of the stem I! about its axis. Inaddition to the cross-sectional shape to prevent rotation, this end I8is preferably tapered so as to wedge itself into the socket in the head10 for retention.

The guard I6 is positioned to be in close proximity but preferably notin direct contact with the outer ends of the brush bristles, Fig. 5, andthe longitudinal marginal edges of the shield or guard terminate in aplane back of the axis of the complished by the shaft ii. In other wordsthese marginal edges do not come around to the diametrical plane of thebrush. Also in this guard 16 there is an outer overturned lip l9, Fig.4, which will form a positive stop and yet at the same time will notinterfele with the use of the end of the brush, particularly when theextreme rear teeth are to be reached.

' The guard I6 is also formed to have a longitudinal channel 20presented along its inner side opening toward the brush. This channel 20has an entrance opening 2| through the lip l9, Fig. 4. This channel 20is provided to form a reservoir to contain a supply of dentifrice in anyof the suitable and well known 'forms. A convenient way for charging thedentifrice into this channel is by means of a capsule 22, Fig. '7,having a water soluble wall and filled with the dentifrice in liquidform, paste form, or powder form. The diameter of the capsule 22 is madeto be such that the bristles of the brush I will be in contact with itas the brush revolves so that, while the capsule wall is soluble itself,the action of the brush thereagainst, will quickly cause the wall tobreak down and release the dentifrice directly onto the brush so thatthe dentifrice is then available and distributed throughout the brushfor application against the teeth.

Some dentists advise that the teeth should always be brushed by carryingthe brush bristles along the teeth substantially vertically and awayfrom the gums. This action is quite readily acinvention by reversing thedirection of rotation of the shaft l2, which, with the use of theelectric motor I I, is readily accomplished by simply reversing themotor in the usual and well known manner by means of a switchcontrolling set of buttons 23 and 24 conveniently located at the end ofthe head where they may be selectively operated by the thumb and indexfinger of the operator. The exact structure of the motor II and of theswitch to be operated by the buttons 23 and 24 are not herein shown indetail for the reason that both are standard constructions readilyobtainable on the market, and their details do not enter per se into thepresent invention. Thus by reversing the direction of rotation of theshaft l3, the brush I5 may be revolved in a direction to carry itsbristles downwardly from the gums of the upper teeth, and then byoperating the shaft in the opposite direction, the brush may be employedon the lower teeth to have the bristles moved upwardly from the lowergums.

As above indicated, by reason of the mounting of the shaft l3 and thestem l1, both of these members may be readily disengaged from the headand other like members substituted for them. This is entirely feasiblein view of the fact that the brush and guard members are relativelyinexpensive as to cost of manufacture. The

flexibility of the stem l1 together with flexibility of the shaft I3make the device more convenient in use to apply the desired pressureagainst the teeth and at the same time prevent damage and injury.Furthermore, by means of this relative flexibility of the two members,the shield or guard l6 may be pressed closer to the brush I! at times,particularly in order to pick up residual quantities of the dentifricewithin the shield.

While the invention has herein been described and shown in the oneparticular form in more or less minute detail, it is entirely obviousthat structural changes may be employed, such as the particular shape ofthe dentifrice retentive and charging means, the shape and design of thehead itself, and the particular holding means for the guard and drivingshaft, all without departing from the spirit of the invention and I,therefore, do not desire to be limited to that precise form beyond thelimitations as may be Y imposed by the following claims.

I claim:

1. The combination with a head and a driving shaft journaled therein, ofa brush; a resilient shaft carrying the brush; means interengaging thebrush shaft with said driving shaft; a brush shield; said brush beingfree to be yieldingly shlftable laterally in respect to said shield; andmeans carried by said head to support said shield in close proximity toand along one side of said brush; said shield positioning meanscomprising a resilient shaft, one end of which is detachably receivedand held against rotation by the head.

2. The combination with a head and a driving shaft carried thereby, of abrush; a resilient shaft carrying the brush; means interengaging thebrush shaft with said driving shaft; a brush shield; said brush beingfree to be yieldingly shiftable laterally in respect to said shield;means carried by said head to support said shield in close proximity toand along one side of said brush; said shield carrying means comprisinga resilient shaft, whereby brush may be laterally shifted one in respectto the other and also collectively in respect to the axis of rotation ofsaid driving shaft; and means carried by said shield for holdingdentifrice to be distributed by said brush whereby the brush and shieldone in respect to the other will effect the removal of the dentifricefrom said holding means.

DWIGHT S. BECKNER.

both the shield and the shifting of

